Earlier quoted context omitted.
The more basic problem is that their methodology would conclude Harry Potter is better than Ulysses, AC/DC is better than Carla Frey, etc etc. It is completely fine to enjoy "dumb" art - I like Marvel comics and a lot of the Disney-era Star Wars novels have been pretty fun. But using easiness and fun as a metric of quality is simply celebrating ignorance and laziness.
Why is Ulysses better than Harry Potter?
I think parent is basing it on high art principles which are: older better, uniqueness, what others agree is valuable and content/quality.
Why aren't we talking about the first english book published? The Recuyell of the Histories of Troye